I own one. Read first then vote and judge. Nobody is selling this for even 15 keys as far as I could find, but because it needs a range, 15 to 18 seems best. Slight bump of high and low ends.

http://www.tf2outpost.com/trade/10160600

Offer of Steaming Tricorne (15.5 keys with overpay) [REJECTED]

Offer of 19 keys [bought something else]

http://www.tf2outpost.com/trade/11371510

offer of 17 keys roughly

http://www.tf2outpost.com/trade/11529235

My trade: 30 dollar offer, about 17 keys pure

http://www.tf2outpost.com/trade/11386787

Offer of bliz sack + der wintermantle, which is about 18.5 keys pure with overpay

http://www.tf2outpost.com/trade/4633045

Bubbling L'inspecteur [about 15 keys with overpay]

Steaming Tricorne [about 15.5 keys with overpay]